So far be it from me to pooh-pooh the Viagra-like performance of Hong Kong’s market since it reopened after a 5-day weekend. Hong Kong’s benchmark index has popped up more than 7% in just two days, pushing it to its highest in seven years and making one of the world’s largest and most established financial centers look like some Silicon Valley startup on its first day of trading. But as my colleague Thomas Streater writes, the rally still has legs, so it’s best just to...